Abstract The naturally configurated S ‐[(2 R )‐2‐acetamido‐3‐(hexadecyloxy)propyl] 2‐(trimethylammonio)ethyl thiophosphate ( 5 ), a new amido‐thiophosphate analog of the Platelet Activating Factor (PAF), was obtained in a seven‐step reaction sequence by starting from N ‐acetyl‐ l ‐cysteine ( 6 ).